function Bromise(executor) {
  var onResolve_ = null
  var onReject_ = null
    // 模拟实现 resolve 和 then，暂不支持 rejcet
  this.then = function(onResolve, onReject) {
    onResolve_ = onResolve
  };

  function resolve(value) {
    setTimeout(function() {
      onResolve_(value)
    }, 0)
  }
  executor(resolve, null);
}

new Bromise((resolve, reject) => {
  resolve('resolve')
})